RoboSimian—an ape-like robot developed by researchers at Caltech, JPL, and UC Santa Barbara—grabbed a fifth-place finish at last weekend's DARPA Robotics Challenge Finals. The 23 teams in the competition were challenged to design a robot that could perform a series of tasks that would be necessary for response during a natural or man-made disaster—tasks such as opening a door, cutting through walls, closing valves, moving debris, and even driving a vehicle.

Although the tasks were performed by the robot's hardware—designed at JPL—the robot was operated by software that included algorithms, or mathematical principles, contributed by Caltech's Joel Burdick, the Richard L. and Dorothy M. Hayman Professor of Mechanical Engineering and Bioengineering; current Caltech graduate student Krishna Shankar; and Burdick's former students Jeremy Ma (MS '05, PhD '10), Nick Hudson (MS '05 PhD '09), and Paul Hebert (MS '07, PhD '13) at JPL.

A powerful partnership leads to advances in islet-cell transplants to treat diabetes

Living with type 1 diabetes today is typically manageable thanks to advancements in medical technology. However, some patients still confront severe complications, from extreme hypoglycemia that can lead to diabetic coma to long-term effects, such as blindness, nerve damage, and kidney failure. In some cases, type 1 diabetes can be life-threatening, and in all cases, it is currently incurable.

But there is hope, fostered by a collaboration between Caltech and its neighbor in Duarte, City of Hope. Established in 2008 with a $6 million gift from an anonymous donor, the Caltech-City of Hope Biomedical Research Initiative provides seed grants to accelerate the development of basic scientific research and its translation into applications ranging from new pharmaceuticals to medical devices to treatment methods. The partnership was formalized—and further strengthened—in 2014, when the two institutions signed a memorandum of understanding, encouraging researchers to collaborate and share resources.

Leadership from Caltech and City of Hope and members of the public celebrated the partnership at a special event on May 13. More than 70 attendees gathered in Caltech's Beckman Institute Auditorium to learn about progress in fighting diabetes.

"The benefits of the deepening relationship between our two institutions emerged clearly in the evening's events," says Caltech President Thomas F. Rosenbaum, holder of the Sonja and William Davidow Presidential Chair and professor of physics. "Our increasing set of research interactions is making great strides in translating fundamental science to advance human health."

To date, the initiative has funded 28 endeavors led by teams of Caltech and City of Hope investigators—early-stage research projects that might not have moved forward if they had had to rely on traditional funding sources.

"The more we work together, the more we enable discovery," says City of Hope president and CEO Robert Stone. "Saving lives today and tomorrow—that's what this collaboration is about."

One encouraging development for people facing uncontrolled type 1 diabetes comes in the form of a simple surgery. The procedure takes healthy, functioning pancreatic islets—clusters of cells that contain insulin-producing beta cells—from an organ donor and transplants them into a patient's liver. Doctors at City of Hope have already performed the surgery on a limited number of patients and have seen promising results.

While islet transplantation eventually may lead to a cure for diabetes, challenges remain in making it practical. Once islets have been donated, for example, how can they be isolated and kept functional? How do researchers distinguish good islets from bad without wasting the good ones during testing?

Through the Caltech-City of Hope Biomedical Research Initiative, researchers and clinicians are working hand-in-hand to answer these important questions.

At the event, researchers told the story and explained the science behind their project. Fouad Kandeel, chair and professor in the Department of Clinical Diabetes, Endocrinology, and Metabolism at City of Hope, and his colleague, Kevin Ferreri, associate research professor in the Division of Developmental and Translational Diabetes and Endocrine Research, have been working on islet cell transplantation as a treatment for their patients with type 1 diabetes. Yet existing methods of selecting islets took too much time, involved too much labor, and used up too many islets.

That is where the Caltech partners came in. Yu-Chong Tai, the Anna L. Rosen Professor of Electrical Engineering and Mechanical Engineering, and Hyuck Choo, assistant professor of electrical engineering and medical engineering, invented a novel device that can screen individual islets. The microfluidic platform accurately determines the health of an islet sample by applying glucose and measuring the sample's reaction. In less than a year, the team has designed a proof-of-concept platform.

Once the device is perfected, Choo believes the team will be able to easily scale it up and even use its technology to help overcome other clinical challenges.

The celebration, open to all members of the Caltech community, included tours of the reimagined space, laboratory demonstrations, and research poster presentations, as well as remarks from key administrative leaders and donors who were instrumental in transforming the Gates-Thomas Laboratory from the mid-twentieth century to the present.

Over the last year, the building—formerly known as the Franklin Thomas Laboratory of Engineering—was modernized with both the lab's history and the future in mind. With a nod to the past, the renovation includes the building's original iron railings as well as artistic etchings and imagery that reference prior research in earthquake engineering and hydrodynamics. Looking to the future, the energy-efficient, renovated building features state-of-the-art laboratories and experimental and computational facilities, along with open spaces where faculty, scholars, and students—including the department's roughly 70 graduate students and 100 undergraduates—can share ideas across disciplines. The upgrades, which were conducted using sustainable building practices and make Gates-Thomas Laboratory eligible for LEED Gold certification, include LED lighting, smart occupancy controls, the use of low-flow fixtures, and, in the public spaces outside, the installation of a drip-irrigation system with landscaping featuring native plants adapted to the local climate.

"These beautiful public spaces . . . the amphitheater directly behind me, which connects the Gates-Thomas Laboratory to the Sherman Fairchild Library, and the Housner Lounge at the heart of the second floor of the building . . . are hubs of activity not only for one department, but across our division and across the Institute," said Ares Rosakis, the Otis Booth Leadership Chair of EAS and the Theodore von Kármán Professor of Aeronautics and Mechanical Engineering, in remarks prior to the official ribbon-cutting ceremony.

"Caltech is a destination for people who want to fulfill their dreams—their dreams of discovery in science and engineering," President Thomas F. Rosenbaum said. "It is as Ares pointed out: Our shared culture, our belief in excellence, our belief in focus, our belief in ambition; the intimacy and intensity of work that gives us the leg up where people can see—whether they are students, faculty, or staff, trustees, friends of the Institute—can see that this is the place where those dreams can be realized.

"When we attract people here, and we tell them about this culture, when they hear and know about this culture, it goes a long way, but it's not enough," Rosenbaum added. "We also need the tools that allow them to succeed; that allow them to make those discoveries that will transform the world. And it is buildings like Gates-Thomas—the environment that has been created this way—that gives them the confidence, that gives them the ability to be able to make those discoveries."

The laboratory is named after two stewards of the Institute: Charles C. Gates Jr. (1921–2005), a businessman, philanthropist, and longtime Caltech trustee; and Franklin Thomas (1885–1952), first chair of the division that became EAS, as well as a civil engineering professor and the dean of students. The renovation was supported by the Gates Frontiers Fund through the guidance of Diane G. Wallach and John S. Gates; the Fred L. Hartley Family Foundation; James E. Hall (BS '57) and his wife, Sandy; and Li-San Hwang (PhD '65) and his wife, Anne.

"We are here today, giving to this project, because it's got a future," said Wallach, Gates's daughter. She noted how proud her father would be today to see the building and the work it will enable. "Charlie would be the first to applaud working together in hopes of reducing our dependence on shrinking public funding, innovating in the classroom, finding ways to leverage great learning and brain power, engaging industry and local communities in our efforts, and streamlining how we move ideas from labs into the marketplace. Certainly this facility behind us came together in this spirit, and I think that is what he would have been so excited to celebrate today."

It is no secret that Caltech's graduate students have unparalleled research opportunities. Working closely with faculty advisers and colleagues in diverse fields across campus, their contributions are essential to the Institute's advances in science, engineering, and technology. For nearly two decades, the Everhart Lecture Series has provided a venue to highlight graduate student research at Caltech.

The annual series, named after Caltech president emeritus Tom Everhart, provides three carefully selected graduate students with an opportunity to present their work to an Institute-wide audience. The series was established with the goal of "encouraging interdisciplinary interaction and helping faculty and graduate students across campus to share ideas about recent research developments, problems and controversies, and to recognize the exemplary presentation and research abilities of Caltech's graduate students."

"Having the ability to demonstrate your work to the broader community—those outside of your own scientific area—is extremely important, and too often graduate students have very little experience with this," says graduate student Constantine Sideris, the 2014–15 chair of the Everhart Lecture Series committee, an interdisciplinary committee of graduate students that selects the three graduate student lecturers from a pool of more than a dozen applicants each fall.

"This series allows them to hone their presentation and dynamic speaking skills, and also their ability to explain difficult, technical concepts to a diverse audience," Sideris says.

This year's lecturers—Carissa Eisler (chemistry and chemical engineering), Roarke Horstmeyer (electrical engineering), and Peter Rapp (chemistry and chemical engineering)—gave talks on campus earlier this spring, and all three were invited to share their work with members of the Caltech community during the Institute's annual Seminar Day event in May. This year's lectures span a range of topics, from enhancing solar-cell efficiency, to improving microscope imaging, to understanding polymers. (Complete lecture descriptions from the students as well as links to podcasts of the recorded talks on iTunes U can be found below.)

"Research is only getting more interdisciplinary, so effectively communicating your work is an essential skill," says Eisler. "The lecture was really challenging, and I was very nervous, but it was incredibly rewarding, and I'm so glad that I did it."

Eisler and her colleagues noted that participating in the lectures provided valuable learning opportunities—by forcing them to synthesize and explain their work to individuals outside of their respective fields—and helped to build campus awareness for the breadth of research that's being done by graduate students.

"I work with a team of remarkable people, and I hope the lecture communicated that my project is just one among many exciting projects in our lab," Rapp says.

Lecture Descriptions:

Building a Brighter Future: Spectrum-Splitting as a Pathway for 50% Efficiency Solar CellsBy Carissa EislerLab: Harry Atwater, Howard Hughes Professor of Applied Physics and Materials Science and director of the Resnick Sustainability Institute

Although possible, ultra-high solar-cell efficiencies (>50 percent) have not been achieved because of limitations by current fabrication methods. Spectrum-splitting modules, or architectures that employ optical elements to divide the incident spectrum into different color bands, are promising because they can convert each photon more efficiently than traditional methods. This talk discusses our design and prototyping efforts to create such a spectrum-splitting module. We explore the spectrum-splitting optics and geometric optimizations in the context of high-efficiency designs. We show a design that achieves 50 percent efficiency with realistic device losses and geometric constraints.

Optical aberrations limit the size of current microscope images to tens of megapixels. This talk will present a method to boost a microscope's resolving power to one gigapixel using a technique termed Fourier ptychography. No moving parts or precision controls are needed for this resolution enhancement. The only required hardware is a standard microscope, which we outfit with a digital detector and an array of LEDs. An optimization algorithm does the rest of the work. Example applications of our new microscope include full-slide digital pathology imaging, wide-scale surface profile mapping of human blood, and achieving sub-wavelength resolution without needing oil immersion.

What if you could give a polymer hands and feet and watch it move? We have developed biological approaches to synthesizing functional materials made from proteins, nature's flagship polymers. These approaches provide a set of tools for answering fundamental questions in polymer physics and for synthesizing dynamic materials that find applications in soft-tissue engineering and regenerative medicine. This talk will explore the dynamics of a model "sticky" polymer: an artificial protein engineered with associative endblocks that self-assembles into viscoelastic hydrogels. Fluorescence relaxation studies have demonstrated that polymer diffusion in these gels is controlled by endblock exchange, a process akin to a molecular handshake. Genetic approaches to modifying the endblock architecture enable tuning of polymer mobility over a wide range.

Caltech and Amgen have joined forces in the pursuit of foundational discoveries in the biological sciences through a multifaceted new partnership spanning research, graduate student training, and shared resources.

"The work we do is built upon the foundation of basic discoveries in biology," says Alexander Kamb (PhD '88), Amgen's senior vice president of Discovery Research. "We look forward to strengthening and extending this foundation through our connection with Caltech."

Caltech received its first gift from Amgen in 1981, just one year after the company was formed. Over the past three decades, Amgen has provided support for a variety of educational programs and investigations at Caltech. Today, Amgen has grown to be one of the world's leading independent biotechnology companies, and it has now entered into a collaborative research agreement for joint investigations with Caltech that will leverage the two institutions' strengths in discovery, and translational and clinical science.

Under the terms of the new agreement, Amgen will fund up to five research projects per year for three years. Bridging the divisions of Chemistry and Chemical Engineering, Biology and Biological Engineering, and Engineering and Applied Science, the projects will focus on large- and small-molecule drug discovery, drug-delivery devices, and diagnostic technologies. Amgen will also provide support for Amgen Graduate Student Fellows in Caltech's interdisciplinary Graduate Program in Biochemistry and Molecular Biophysics.

In addition to fellowship and research support, Amgen has chosen Caltech as its first partner to access the Amgen Biology-Enabling Resource, a searchable database comprising more than 1,000 items, including molecules, peptides, antibodies, and engineered cell lines acquired through years of discovery efforts. Amgen will have no claim to ownership of intellectual property to discoveries that may ensue. Over time, Amgen will extend access to other research institutions and, as specific materials are depleted, add others to the catalog.

This comprehensive agreement with Amgen exemplifies Caltech's commitment to building strategic partnerships to optimize the Institute's capabilities and help solve pressing problems for the benefit of the public. This and other such relationships with corporations, government agencies, non-governmental organizations, and other institutions, focus on transferring technology from Caltech's campus to industry.

"Each industry collaboration has a unique scope and focus, but all share a goal of transforming new research findings into applications that will benefit society," explains Caltech Vice Provost, Mory Gharib, the Hans W. Liepmann Professor of Aeronautics and Bioinspired Engineering. "The hope is that the Caltech–Amgen partnership will enable our teams to swiftly convert laboratory discoveries into therapeutics or devices that will improve patients' lives."

Caltech seniors Jonathan Liu, Charles Tschirhart, and Caroline Werlang will be engaging in research abroad as Fulbright Scholars this fall. Sponsored by the Department of State's Bureau of Educational and Cultural Affairs, the Fulbright Program was established in 1946 to honor the late Senator J. William Fulbright of Arkansas for his contributions to fostering international understanding.

Jonathan Liu is an applied physics major from Pleasanton, California, who will be doing research at Ludwig Maximilian University Munich in Germany. He plans to work with a biophysicist studying how DNA moves in a liquid with a thermal gradient, which could shed light on the molecular origins of life. Long strands of DNA should break apart well before they have time to organize themselves into the complicated arrangements needed to be self-reproducing, but previous work in the lab Liu is joining has hinted that deep-sea hydrothermal vents may have allowed long strands to form stable clusters. Liu plans to enroll at UC Berkeley for graduate study in physics at the PhD level on his return; he was awarded one of UC Berkley's Graduate Student Instructorships to support his work.

Charles Tschirhart of Naperville, Illinois, is a double major in applied physics and chemistry. He will be studying condensed matter physics at the University of Nottingham, England, where he plans to develop new ways to "photograph" nanometer-sized (billionth-of-a-meter-sized) objects using atomic force microscopy. He will then proceed to UC Santa Barbara to earn a PhD in experimental condensed matter physics. Charles has won both a Hertz fellowship and National Science Foundation Graduate Research Fellowship; both will support his PhD work at UC Santa Barbara.

Caroline Werlang, a chemical engineering student from Houston, Texas, will go to the Institute of Bioengineering at the École Polytechnique Fédérale de Lausanne in Switzerland to work on kinases, which are proteins that act as molecular "on/off" switches. She will join a lab that is trying to determine how kinases select and bind to their targets in order to initiate or block other biological processes—an important step toward designing a synthetic kinase that could activate a tumor-suppressor protein, for example. After her Fulbright, she will pursue a doctorate in biological engineering at MIT. Caroline's PhD studies will be supported by a National Science Foundation Graduate Fellowship.

The Fulbright Program is the flagship international exchange program sponsored by the U.S. government. Seniors and graduate students who compete in the U.S. Fulbright Student Program can apply to one of the more than 160 countries whose universities are willing to host Fulbright Scholars. For the academic program, which sponsors one academic year of study or research abroad after the bachelor's degree, each applicant must submit a plan of research or study, a personal essay, three academic references, and a transcript that demonstrates a record of outstanding academic work.

A team of biologists and a mathematician have identified and characterized a network composed of 94 proteins that work together to regulate fat storage in yeast.

"Removal of any one of the proteins results in an increase in cellular fat content, which is analogous to obesity," says study coauthor Bader Al-Anzi, a research scientist at Caltech.

The findings, detailed in the May issue of the journal PLOS Computational Biology, suggest that yeast could serve as a valuable test organism for studying human obesity.

"Many of the proteins we identified have mammalian counterparts, but detailed examinations of their role in humans has been challenging," says Al-Anzi. "The obesity research field would benefit greatly if a single-cell model organism such as yeast could be used—one that can be analyzed using easy, fast, and affordable methods."

Using genetic tools, Al-Anzi and his research assistant Patrick Arpp screened a collection of about 5,000 different mutant yeast strains and identified 94 genes that, when removed, produced yeast with increases in fat content, as measured by quantitating fat bands on thin-layer chromatography plates. Other studies have shown that such "obese" yeast cells grow more slowly than normal, an indication that in yeast as in humans, too much fat accumulation is not a good thing. "A yeast cell that uses most of its energy to synthesize fat that is not needed does so at the expense of other critical functions, and that ultimately slows down its growth and reproduction," Al-Anzi says.

When the team looked at the protein products of the genes, they discovered that those proteins are physically bonded to one another to form an extensive, highly clustered network within the cell.

Such a configuration cannot be generated through a random process, say study coauthors Sherif Gerges, a bioinformatician at Princeton University, and Noah Olsman, a graduate student in Caltech's Division of Engineering and Applied Science, who independently evaluated the details of the network. Both concluded that the network must have formed as the result of evolutionary selection.

In human-scale networks, such as the Internet, power grids, and social networks, the most influential or critical nodes are often, but not always, those that are the most highly connected.

The team wondered whether the fat-storage network exhibits this feature, and, if not, whether some other characteristics of the nodes would determine which ones were most critical. Then, they could ask if removing the genes that encode the most critical nodes would have the largest effect on fat content.

To examine this hypothesis further, Al-Anzi sought out the help of a mathematician familiar with graph theory, the branch of mathematics that considers the structure of nodes connected by edges, or pathways. "When I realized I needed help, I closed my laptop and went across campus to the mathematics department at Caltech," Al-Anzi recalls. "I walked into the only office door that was open at the time, and introduced myself."

The mathematician that Al-Anzi found that day was Christopher Ormerod, a Taussky–Todd Instructor in Mathematics at Caltech. Al-Anzi's data piqued Ormerod's curiosity. "I was especially struck by the fact that connections between the proteins in the network didn't appear to be random," says Ormerod, who is also a coauthor on the study. "I suspected there was something mathematically interesting happening in this network."

With the help of Ormerod, the team created a computer model that suggested the yeast fat network exhibits what is known as the small-world property. This is akin to a social network that contains many different local clusters of people who are linked to each other by mutual acquaintances, so that any person within the cluster can be reached via another person through a small number of steps.

This pattern is also seen in a well-known network model in graph theory, called the Watts-Strogatz model. The model was originally devised to explain the clustering phenomenon often observed in real networks, but had not previously been applied to cellular networks.

Ormerod suggested that graph theory might be used to make predictions that could be experimentally proven. For example, graph theory says that the most important nodes in the network are not necessarily the ones with the most connections, but rather those that have the most high-quality connections. In particular, nodes having many distant or circuitous connections are less important than those with more direct connections to other nodes, and, especially, direct connections to other important nodes. In mathematical jargon, these important nodes are said to have a high "centrality score."

"In network analysis, the centrality of a node serves as an indicator of its importance to the overall network," Ormerod says.

"Our work predicts that changing the proteins with the highest centrality scores will have a bigger effect on network output than average," he adds. And indeed, the researchers found that the removal of proteins with the highest predicted centrality scores produced yeast cells with a larger fat band than in yeast whose less-important proteins had been removed.

The use of centrality scores to gauge the relative importance of a protein in a cellular network is a marked departure from how proteins traditionally have been viewed and studied—that is, as lone players, whose characteristics are individually assessed. "It was a very local view of how cells functioned," Al-Anzi says. "Now we're realizing that the majority of proteins are parts of signaling networks that perform specific tasks within the cell."

Moving forward, the researchers think their technique could be applicable to protein networks that control other cellular functions—such as abnormal cell division, which can lead to cancer.

"These kinds of methods might allow researchers to determine which proteins are most important to study in order to understand diseases that arise when these functions are disrupted," says Kai Zinn, a professor of biology at Caltech and the study's senior author. "For example, defects in the control of cell growth and division can lead to cancer, and one might be able to use centrality scores to identify key proteins that regulate these processes. These might be proteins that had been overlooked in the past, and they could represent new targets for drug development."

CTLO Presents Ed Talk Week 2015

Today we celebrate Ditch Day, one of Caltech's oldest traditions. During this annual spring rite—the timing of which is kept secret until the last minute—seniors ditch their classes and vanish from campus. Before they go, however, they leave behind complex, carefully planned out puzzles and challenges—known as "stacks"—designed to occupy the underclassmen and prevent them from wreaking havoc on the seniors' unoccupied rooms.

Follow the action on Caltech's Facebook, Twitter, and Instagram pages as the undergraduates tackle the puzzles left for them to solve around campus. Join the conversation by sharing your favorite Ditch Day memories and using #CaltechDitchDay in your tweets and postings.

Conserving a museum's holdings is a blend of art and science. Analytical chemists have explained why a dramatic sky disappeared from Winslow Homer's For to Be a Farmer's Boy. Materials scientists have unearthed the sources of color in ancient Chinese jades. Environmental engineers have uncovered the reasons behind the faded brilliance of Georges Seurat's A Sunday on La Grande Jatte.

On Wednesday, May 20, at 8 p.m. in Caltech's Beckman Auditorium, Katherine T. Faber, the Simon Ramo Professor of Materials Science at Caltech, will examine how science serves art in a museum setting, and discuss how bridges to universities can be built.

Q: What do you do?

A: I am a materials scientist who focuses on the mechanical behavior of brittle materials. Ceramic materials are especially attractive for use at very high temperatures, such as those needed for energy-related applications—engine components, catalyst supports, or coatings for turbines in aerospace or power generation.

And when I say "mechanical behavior," I'm largely interested in how materials fracture. I'm pretty fortunate to be able to break things for a living. But I have also discovered through the years that some of the materials and structures that I want to study don't exist. That has forced me to move into ceramic processing as well. That way my students and I can understand the link between how the materials are made and how they respond.

Our recent work has focused on porous materials. Historically, one would not want pores in brittle materials, because they act as flaws, and therefore as sources of failure. More recently, porosity is desirable in ceramics, for high-temperature filters or for biomedical scaffolds that allow cell or bone ingrowth, to name just two examples.

Q: How does that relate to art conservation, which is the subject of your talk?

A: Conservation studies have actually become an important part of my career. Objects of cultural heritage are made up of the same materials that we study as materials scientists. The phenomena that occur in cultural heritage materials are of particular interest—one needs to understand degradation, such as fading or cracking, in order to preserve these objects. The merit of these studies reaches beyond the art community. We all benefit from these investigations. So will our children, if we continue to study and protect our cultural heritage.

Engineering disciplines are generally very forward thinking and future-oriented. We say, "What materials can we make that will improve our future?" But it is also of value to take our knowledge of materials and look back. One aspect of this art-related work that has been appealing to students is the realization that the expertise that they are developing can be used to solve many different kinds of problems. It's not just about the next photovoltaic or the next superalloy—their talents and skills can be put to use in technical art history. Ultimately, I would like to develop partnerships here in Southern California that will offer Caltech students the same opportunities that the students at Northwestern University have had with the Art Institute of Chicago. It's simply a matter of finding the right partners in the broad array of museums we have here.

Q: How did you get into this line of work?

A: Quite by chance. About 12 years ago, I was approached by staff from the Art Institute of Chicago, which had just been given funds to hire its very first conservation scientist. The museum had a very large conservation department, but it did not have a PhD-level scientist on board. The staff was trying to anticipate the needs of this person, who had yet to be named. They were hoping to identify contacts in the academic community for their future hire, and they had heard about my department's reputation. I was the chair of Northwestern's Department of Materials Science and Engineering at the time, so I was the natural person to visit. When asked if we might be a good link for their scientist, my response was an immediate "Yes!"

And indeed, a year later the Art Institute hired a fantastic conservation scientist, Francesca Casadio, and we started to work together immediately. We've collaborated on ancient Chinese jades and Meissen ceramics. I also became the matchmaker, if you will, who linked other engineering faculty at Northwestern to the Art Institute. In 2013, Francesca and I went on to found the Center for Scientific Studies in the Arts, a partnership funded by the Andrew W. Mellon Foundation, extending our research to museums around the U.S. But it was all serendipity.

Named for the late Caltech professor Earnest C. Watson, who founded the series in 1922, the Watson Lectures present Caltech and JPL researchers describing their work to the public. Many past Watson Lectures are available online at Caltech's iTunes U site.